Ripper attachment for tractor



Sept. 8, 1970 R. J. BERNOTAS ET Al.

RIPPER ATTACHMENT FOR TRACTOR 2 She ets-Sheet 1 Filed June 9. 1967 Sept. 8, 1970 BERNOTAS ET AL 3,527,308

RIPPER ATTACHMENT FOR TRACTOR Filed June 9, 1967 2 Sheets-Sheet 2 INVENTORS AaJu/r 1.5mm:

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Char/e5 A? A a/125 ATTORNEY United States Patent 3,527,308 RIPPER ATTACHMENT FOR TRACTOR Ralph J. Bernotas, South Euclid, Ronald M. Cheers,

Timberlake, and Charles R. Holub, Solon, Ohio, as-

signors to General Motors Corporation, Detroit, Mich.,

a corporation of Delaware Filed June 9, 1967, Ser. No. 644,938 Int. Cl. A01b 63/32, 63/102 US. Cl. 172-464 1 Claim ABSTRACT OF THE DISCLOSURE There are two basic types of rippers presently used with tractors; one being the radial-lift type ripper and the other the so-called parallel-lift ripper. As is well known to those skilled in the art, the radial-lift ripper permits the shank to be raised and lowered through an arc while the parallel-lift ripper incorporates a parallelogram linkage for maintaining the shank in a substantially vertical plane as it moves between a raised and a lowered position.

The parallel-lift type ripper is gaining popularity among contractors because it offers a constant ripping angle for the point and, thus, efiicient ripping regardless of the depth of earth penetration. Another advantage of this form of ripper is that the constant angle feature prevents the point from being dragged along the ground prior to reaching penetration depth as in the case of the radial-lift ripper. As a result, point wear is reduced to a minimum when operating abrasive materials such as sandstone.

Although the parallel ripper enjoys the advantages described above, one difliculty with this type of device is that during a raising operation, the point moves toward the tractor and can therefore wedge large slabs, boulders, or the like, between the rear of the tractor and the point. Another drawback has been the inability of the operator to vary the angle of the point and therefore determine the optimum ripping angle for the type of material being ripped.

Accordingly, the objects of the present invention are to provide a parallel-lift ripper having a point that can be angularly varied during a ripping operation; to provide a ripper having a linkage arrangement that permits the ripper to assume a desired ripping angle and maintain substantially such angle while being lowered to penetration depth; to provide a linkage for a parallel ripper that includes means for moving the ripper tooth away from the tractor while at penetration depth; and to provide a parallelogram linkage for a ripper having one link thereof that can be varied in length and thereby cause the point to change its angular relationship While maintaining a constant ripping depth.

Other objects and advantages of the present invention will be more apparent from the following detailed description when taken with the drawings in which:

FIG. 1 is a perspective view showing a ripper attachment made in accordance with the invention and secured to the rear of a crawler tractor;

FIG. 2 is an elevation view of the ripper attachment 3,527,308 Patented Sept. 8, 1970 shown in FIG. 1 and shows the latter in the lowered-rip position;

FIG. 3 is a view similar to FIG. 2 but shows the ripper attachment in the raised-carry position, and

FIG. 4 is an end view taken on line 44 of FIG. 2.

Referring to FIG. 1, a ripper attachment 10 made in accordance with the invention is shown rigidly secured to the rear end of a crawler tractor 12 having the usual endless tracks 14 and 16 respectively entrained about driving sprockets 18 and 20. The ripper attachment 10 comprises, in general, a mounting frame 22 which pivotally supports a pair of laterally spaced arms 24 and 26 which, in turn, are pivotally connected to and support a shank assembly 28. A pair of double-acting hydraulic jacks 30 and 32 are connected between the mounting frame 22 and the arms 24, 26 for purposes of moving the shank assembly 28 between a lowered-rip position, as shown in FIG. 2, and a raised-carry position as shown in FIG. 3. A third double-acting hydraulic jack 34 extends between the central portion of the frame 22 and the shank assembly 28 for varying the angular relationship of the latter with respect to the ground about a transverse horizontal axis in a manner to be described in detail hereinafter.

More specifically, the mounting frame 22 includes a pair of upstanding brackets 36 and 38 rigidly connected to a rectangular mounting block 40 which is adapted to be secured through bolts or the like to the tractor. Both of the brackets 36 and 38 are identical in form and comprise a pair of spaced plates, the upper ends of which extend rearwardly to provide transversely aligned pivotal connections 44 and 46 for respectively supporting the cylinder ends of the double-acting jacks 30 and 32. The lower ends of the respective brackets pivotally support the forward ends of the arms 24 and 26 for movement about a transverse horizontal axis passing through pivotal connections 48 and 50. The arms 24 and 26 extend rearwardly from the points 48 and 50 for pivotal attachment with the shank assembly 28 and serve to support the latter for rotational movement about a horizontal axis passing through the pivotal connections 52 and 54. It will be understood that although the arms 24 and 26 are shown to be independently supported by the brackets, they are intended to operate together and therefore could be interconnected through a cross member if so desired. Moreover, it will be noted that the piston rod portions of the jacks 30 and 32, respectively are connected to the arms 24 and 26 at intermediate points thereof by pivotal connections 56 and 58.

As shown in FIGS. 1, 2, and 4, a support car 60 is rigidly connected to the mounting block 40 between the brackets 36 and 38. The support ear 60 is provided with a pivotal connection 62 which serves to support the cylinder end of the hydraulic jack 34 which extends rearwardly for pivotal connection at a point 64 with a forwardly projecting flange 66 secured to the shank assembly 28.

The shank assembly 28 consists of a transversely extending box section or beam 68, the end portions and central portion of which are formed with identical pockets 70 which serve to fixedly support shanks 72, 74, and 76. The lower ends of the shanks are provided with the usual detachably mounted ripper tooth or point 78.

It should be apparent from the above description that by expansion or contraction of the jack 34, the shank assembly 28 can be angnlarly adjusted about the aligned about the aligned pivotal connections 52 and 54 with the support arms so as to vary its relationship with the ground. Moreover, during operation, the shank assembly 28 can be moved from the raised-carry position of FIG. 3 to the lowered-rip position of FIG. 2 by expanding the jacks 30 and 32. In this connection and assuming the jack 34 is in the full line position of FIG. 3, the shanks 72, 74, and 76 will move downwardly in a subs'tantially vertical plane extending transversely of the tractor until the penetration depth of FIG. 2 is realized. During such time the driving power of the tractor will cause the ripper tooth to rip the material at the established depth and, when the ripping operation is completed, the shank assembly 28 may be raised out of the ground by contracting the cylinders 30 and 32. If, however, difficulty should occur in removing the shanks from the ripped material as, for example, due to the ripper point encountering a boulder or the like, the jack 34 may be contracted so as to cause the shank assembly 28 to pivot counterclockwise, as seen in FIG. 2, about its pivotal connecttions 52 and 54 with the support arms 24 and 26. By so doing, the ripper tooth 78 moves rearwardly and thereby facilitates removal of the ripper shanks from the ground. In the embodiment shown in FIG. 2 of the drawings, the extensible link or jack 34 is of a size which provides for rearward movement of the ripper tooth 78 only. However, it will be understood that forward or clockwise movement of the tooth 78 could be accomplished by increasing the stroke of the jack.

Finally, it will be noted that FIG. 3 shows another feature of the present invention; namely, the ability of the shank assembly 28 to have its position varied prior to being lowered into the ground. In other words, by contracting the jack 34, it is possible to move the upper end of the shank assembly 28 counterclockwise about its pivotal connection with the arms and thereby provide an increase in angular penetration of the ripper tooth as seen in phantom lines.

Various changes and modifications can be made in this construction without departing from the spirit of the invention. Such changes and modifications are contemplated by the inventors and they do not wish to be limited except by the scope of the appended claim.

We claim:

1. A ripper attachment for a tractor, comprising a mounting frame adapted to be secured to the rear of the tractor, said frame including upstanding bracket means at either side thereof, support arm means pivotally connected at one end to the lower end of each of the bracket means, a beam member pivotally supported by the opposite ends of said support arms for movement about a transversehorizontal axis, a plurality of ripper shanks supported by said beam member forming a beam and shank assembly, a first double acting hydraulic jack located above the support arm means and substantially parallel thereto, means pivotally connecting one end of said hydraulic jack to said mounting frame, a bracket member secured to said beam member, means pivotally connecting the other end of said hydraulic jack to said bracket member, said hydraulic jack adapted to be expanded and contracted when the tractor is moving and during a ripping operation to cause the beam member and the ripper shanks to vary their angular relationship about said axis with the surface of the ground, a pair of second double-acting hydraulic jacks each being directly pivotally connected between an upper end of said upstanding bracket means and an intermediate portion of said support arm means for raising the beam and ripper shank assembly to raised-carry position and for forcing the beam and shank assembly into the earth while moving to a lower-rip position, said beam and ripper shank assembly being maintained in a vertical plane when said first hydraulic jack is extended and said second hydraulic jacks are operated to raise and lower said beam and shank assembly whereby upon lowering said ripper shanks directly engage the earth, retraction of said first double-acting hydraulic jack rotating said ripper shanks counterclockwise to provide for release of any objects engaged between the shanks and the tractor during raising thereof.

References Cited UNITED STATES PATENTS 2,657,914 11/1953 McMahon 172--506 2,722,181 11/1955 Hash 172444 X 3,002,574 10/1961 Padrick 172-739 X 3,031,208 4/1962 Abbott 172439 X 3,116,797 1/1964 Launder et a1. 172484 X 3,289,771 12/1966 Bennett 172448 X 3,348,383 10/1967 Kelley 172484 X FOREIGN PATENTS 234,013 6/1961 Australia.

ROBERT E. PULFREY, Primary Assistant A. E. KOPECKI, Assistant Examiner us. c1. X.R. 

